This invention relates generally to percussive, down-hole drills, and more particularly to an apparatus for positioning a split retaining ring in a casing of a down-hole drill.
Down-hole drills typically use a set of split retaining ring halves to retain the drilling bit within the casing of the drill. These rings are usually flat and split so they can be axially sandwiched and retained between internal drill parts, i.e. the chuck and the bit bearing.
Due to high levels of vibration and shock in the bit end of a down-hole drill, conventional split retaining rings are prone to move radially back and forth within a space provided by the split between the halves. Such movement of rings can cause a number of problems, namely:
1. rubbing of the rings against the bit causing the bit to crack;
2. incomplete contact between the ring halves and the bit contact shoulder;
3. damage to the contact zone on the bit; and
4. high stresses in the ring halves.
The foregoing illustrates limitations known to exist in present down-hole drills. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.